Tray or box

ABSTRACT

A stackable tray having upstanding projections on its walls and apertures in its bottom, so that a stack of the trays can be stabilized by inter-engagement of the projections and apertures. The projections are provided in at least two corners, and each projection extends laterally around the corner. The angled form of the projection, particularly when made from foldable sheet material, strengthens it against lateral deformation in a stack of filled trays. When used for containing meals or refreshments at least a part of one wall of each tray may be lower than the other walls.

United States Patent Chidgey TRAY OR BOX [72] Inventor: Alfred LeonardChidgey, Downend,

England [73] Assignee: Robinson, ES & A Limited, Bristol,

England [22] Filed: Feb. 2, 1970 [21] Appl. No.: 7,640

[30] Foreign Application Priority Data Jan. 31, 1969 Great Britain......5,'489/69 [52] US. Cl ..229/3 4 R, 229/31 FS [51] Int. Cl. ..B65d5/26 [58] Field of Search ...229/30, 31 R, 31 PS, 32, 34 B,

229/34 R, 35, DIG. ll

[56] References Cited UNITED STATES PATENTS 2,843,307 7/1958 Goltz.....229/34 [151 3,685,718 51 Aug. 22, 1 972 3,520,468 7/1970 3 Weimann..229/45 Primary Examiner-Even C. Blunk Assistant Examiner-Johnny D.Cherry Attorney-Jones and Lockwood 57 ABSTRACT .A stackable tray havingupstanding projections on its walls and apertures in its bottom, so thata stack of the trays can be stabilized by inter-engagement of theprojections and apertures. The projections are provided in at least twocomers, and each projection extends laterally around the comer. Theangled form of the projection, particularly when made from foldablesheet materiaLstrengthens it against lateral deformation in a stack offilled trays. When used for containing meals or refreshments at least apart of one wall of each tray may be lower than the other walls.

13 Claims, 12 Drawing Figures TRAY OR BOX This invention relates totrays and boxes (hereinafter referred to generally as trays). Moreparticularly it relates to stackable trays. It is especially applicableto trays for carrying meals or refreshments, where the trays must forconvenience and saving of space be stacked ready for distribution, andif necessary restacked after use. One problem involved in this is thatof making the stack stable against collapse from minor disturbances,particularly when being handled. Interengagement between adjacent trayswould be a suitable method of achieving this but it must be such thatthe trays can be readily located relative to each other, readily removedfrom the stack, and yet the engagement being strong enough to resistdeformation under the often considerable weight and inertia of thefilled and stacked trays. This problem is particularly acute in traysmade from foldable sheet material since the sheet is normally easilydeformed.

The inventor has found that suitableengagement can be attained betweenprojections on one tray with apertures in an adjacent traywhen theprojections are of angled form; the increased strength being derivedfrom the angular nature of the projections.

Accordingly the present invention provides a stackable tray comprisingabottorn having an aperture in each of at least two corner regions,walls extending upwardly from the bottom and including in each of atleast two comer regions a pair of comer forming panels extending onealong each of the adjacent sides of the tray and having a single.integral projection extending upwardly above the height of the adjacentwalls and laterally around the comer. I

The tray is preferably made from foldable sheet material such ascardboard. It may be of permanent construction or it may be collapsible.

One fonn of tray made from foldable sheet material such as cardboard hashinged to the bottom a pair of opposite side walls and a third side wallextending between them, said third wall having lateral flaps hingedthereto, and each wall of said pair comprising a first panel hinged tothe bottom and a second panel hinged to the first panel and folded intothe tray to trap the adjacent lateral flaps between the panels andthereby maintain the walls in the erect condition, the projections beingprovided at the comers between and integral with said third wall and itslateral flaps. The part of each projection which extends upwardly from alateral flap may pass through a cut-away portion of the adjacent wall ofsaid pair.

Preferably said third wall comprises a first panel hinged to the bottom,a second panel hinged to the outer end of the first panel and foldedback on the first panel and secured in that condition, the lateral flapsbeing hinged to one of the panels, and each projection being provided inpart by an L-shaped cut at the end of the hinge line between the twopanels and extending from the hinge line into the panel not carrying thelateral flaps. The securing may be effected by a flange hinged to thesecond panel and adhered to the bottom, or else the first and secondpanels may be adhered together. Preferably the second panels of saidpair of walls are folded inwardly to trap the lateral flaps, and thesecond panel of each wall of the tray has hinged to it-a flange whichlies on the bottom and faces inwardly from the wall, the length of theflange of said third wall being such that at its ends it abuts the edgesof the flanges of said pair of walls and maintains the second panels ofsaid pair in the folded in condition. Preferably the outer of the twopanels of said third wall is provided with the lateral flaps and theinner of the two is arranged to flex inwardly relative to the box sothat the adjacent ends of the second panels of said pair of walls aretrapped between the lateral flaps and the ends of the inwardly flexedpanel.

In another form of the invention the wall of the tray includes an outerwall forming part, an inner wall forming part fitting inside the outerpart and comprising a strip of panels hinged one to the next, and meansfor retaining the strip within the tray, the upper edge of the stripbeing shaped in the region of the hinges to provide the projections.

The retainingmeans preferably comprises horizontal webs of materialextending diagonally across the corners between adjacent outer wallpanels engaging in corresponding horizontal slots provided in the stripin the region of its hinges and extending into the adjacent panels. Theouter wall panels of the tray are preferably provided with an inturnedperipheral flange providing spacing means between the outer wall panelsand the strip.

The strip may alternatively be secured within the tray by stitching,stapling, or adhering to the inside surfaces of the outer wall panels.

The invention includes a blank of foldable sheet material for erectioninto a tray as hereinbefore described.

The invention further includes a stack of the trays described housed ina container and withdrawable horizontally therefrom.

Two forms of tray made according to this invention and the methodforming a stack from such trays is illustrated in the accompanyingdrawings wherein:

FIG. 1 shows a blank for making one form of tray.

FIG. 2 shows the blank in a partially folded condition.

FIG. 3 shows a perspective view of the partially erected tray.

FIG. 4 shows a perspective view of the fully erected tray.

FIG. 5 shows a perspective fragmentary view of two trays stackedtogether.

FIG. 6 shows a perspective view tray.

FIG. 7 is an exploded perspective view of the tray shown in FIG. 6showing the various integers which make up the tray.

FIG. 8 is a perspective underneath view of a corner of the tray with thebottom removed.

FIG. 9 is a section taken on line IV-IV of FIG. 1.

FIG. 10 is a perspective view of a portion of two trays showing how theycan be stacked together.

FIG. 11 is a perspective view of the same portions of tray as shown inFIG. 5 and viewed from the inside, and

FIG. 12 is a perspective view of a stack of trays in use.

Referring to the drawings, and firstly to FIGS. 1 to 5, the firstembodiment of tray is erected from the blank shown in FIG. 1. This blankcomprises a rectangular bottom forming panel and hinged thereto twopairs of a second form of of opposite side wall forming portions, onepair along the longer sides of the bottom and the other pair along theshorter sides of the bottom.

One of the longer walls is made up from a first panel 102 hinged to thebottom and a second panel 104 hinged at 106 to the free end of the firstpanel. A flange 108 is hinged at 110 to the free end of the second panel104, and a pair of lateral flaps 112 are hinged to the first panel 102.In addition, a pair of L-shaped cuts 114 increase the height of thepanel 102 at its end portions and decrease the overall length of thesecond panel 104. The panels 102, 104 are the same height each side ofthe hinge line 106, so that the panel 104 can be folded back on thepanel 102 and the panel 108 adhered to the bottom over the correspondingarea 116.

The other long wall likewise comprises a first panel 118 hinged to thebottom, a second panel 120 hinged at 122 to the free end of the panel118, and a flange 124 hinged at 126 to the free end of the second panel.Lateral flaps 128 are hinged to the first panel 118, and L-shaped cuts130 increase the height of the first panel 118 at its end portions anddecrease the overall length of the second panel 120 inthe region of itshinge 122. In addition, a medial line of weakening 132 is provided inthe second panel 120. The panels 118, 120 are of equal height each sideof the hinge line 122 so that the panel 120 can be folded back on thepanel 118 and the flange 124 adhered to the bottom over thecorresponding region 134.

The walls at the two shorter sides are of identical construction. Eachcomprises a first panel 136 hinged to the bottom, a second panel 138hinged to the free end of the first panel, and a flange 140 hinged tothe free end of the second panel. The panels 136, 138 are of equalheight each side of the hinge line joining them so that the panel 138can be folded over the panel 136 with the flange 140 abutting the bottom100. In addition, the first and second panels have cut-away regions 142at their ends adjacent the lateral flaps 128, and diagonal lines ofweakening 144 extend across the panels 138 and flanges 140.

Triangular apertures 146 are provided in the bottom 100 near the comersbetween the panel 118 and the panels 136, but spaced from the edges ofthe bottom 100 by amounts equal to the widths'of the flanges 140 and124.

The first stage in erecting thetray consists in folding over the panels104 and 120 and adhering the flanges 108 and 124 to the areas 116 and134 respectively of the bottom. At this stage the blank will still be ina flat condition, so that if the manufacturer wishes to supply blanksfor erection by the customer, they may be supplied either in the formshown in FIG. 1 or the partially folded form shown in FIG. 2. Ifsupplied in the form shown in FIG. 1, a pressure-sensitive or otheradhesive may be applied to the areas 116, 134 and if necessary also tothe flanges 108, 124 before sending out the blanks.

To erect the box from the blank, the two longer walls are brought intothe upright condition and the lateral flaps 112, 128 turned inwardly soas to lie along the hinge lines between the panels 136 and bottom 100.As will be seen from the drawings, the panels 102 and 118 have upwardlytapering sides so that when the lateral flaps I I2, 128 are brought intocontact with the bottom the walls are inclined upwardly inwardlyrelative to the tray.

Next, each panel 136 is erected so that it lies against the adjacentlateral flaps 112, 128, and is thus also inclined upwardly inwardlyrelative to the box. The panels 138 are then turned over into the box soas to trap the lateral flaps between panels 138 and 136, and the flangesare turned inwardly relative to the box and rest on the bottom 100. Theedges of the flanges 140 also abut the end edges of the flanges 124 and108 which assists in maintaining the panels 138 in the folded incondition.

Because of the upwardly convergent attitude of the two longer walls, themaximum lengths of the panels 138 is greater than the distance betweenthe upper edges of the longer walls. Thus, the diagonal line ofweakening 144 is provided in the panels 138 to allow them to flex andfacilitate their entry into the tray. Furthermore, the medial line ofweakening 132 in the panel 120 allows this panel to flex inwardlyrelative to the box when the wall is brought into the upright condition.Thus the adjacent ends 148 of the panels 138 can be trapped between thelateral flaps 128 and the edges 150 of the panel 120. This retains thepanels 138 in the correct position, and prevents the apertures 146 frombeing partially covered by the flanges 140.

The upper edge of each lateral flap 128 is stepped at 154 so as toprovide, together with the adjacent L- shaped cut 130, an upstandingprojection 152 in the corner of the tray. In the erected condition ofthe tray, each projection 152 emerges in part through the cut awayregion 142 of the shorter wall, thus projecting upwardly above theheight of the adjacent walls, and laterally around the corner.

The upward taper at the sides of the panels 102, 118 is designed so thatthe resulting overhang of the side walls will bring the projections 152into register with (that is vertically above) the apertures 146. Thus,as shown in FIG. 5, two similar trays can be stacked one on top of theother with the projections of the lower tray extending into theapertures 146 of the upper tray, the upper edges of the side wallsbetween the projections providing a seating for the bottom of the trayabove. Any number of trays can be stacked one above the other in thisway.

Referring now to the second embodiment shown n FIGS. 6 to 11 of thedrawings; each tray comprises three parts,v a bottom part A, and twowall forming parts B and C. The bottom part A comprises a rectangularbottom forming area 2 with hinged side panels, comprising a front panel4, a rear panel 6 and end panels 8 joined to the bottom forming area 2through fold lines. The bottom area is provided with a pair oftriangular apertures 9 in the comer regions adjacent the rear panel 6.

The wall fonning part B is of rigid construction and comprises a frontwall panel 10, a rear wall panel 12 and end wall panels 14 joinedtogether to form a frame with a peripheral intumed continuous andhorizontal flange comprising a front portion 16, a rear portion 18 andend portions 20. Each corner between the portions 16 and 20 is formed asa horizontal web 22. Each corner between the portions 18 and portion 20is also formed as a horizontal web 24, the edge of the webs 24 beinginclined relative to the wall panels 14 at a slightly different anglethen are the edges of the webs 22.

The wall forming part C comprises a strip of three panels hingedone tothe next; a back panel 26 and two end panels 28 joined to the panel 26through fold lines 30. The panels 26 and 28 are provided each with aflange 32 joined to the lower edges of the panels through score lines.The panels 28 are provided at their free ends with tabs 34 and cut outslots 36 from each of which leads a slit 38. The part C is furtherprovided with a pair of recesses 42 extending from the bottom of theblank across the fold lines 30 so as to be partly in the panel 26 andpartly in the panels 28. A slot 44 extends across each fold line 30above the recess 42 and the upper edge of the blank is shaped to providea pair of projections 46 each of which also extends across a fold line30, the remainder of the upper edge forming a shoulder for supporting asimilar tray stacked on top.

The tray is assembled by applying the panels 4, 6'and 8 to the innerfaces of the panels 10, 12 and 14respectively by means of adhesive orother means. The part C is applied to the inner edge of the wall portionB by bringing the ends of the panels 28 close together and making theslots 44 to engage the webs 22. The free ends of the panels 28 are thenbrought outwards so that the slots 36 engage the webs 24 and the sidesof the slits 38 grip the two surfaces of the webs 24. In this positionthe tabs 34 lie on the inside of the wall 10. The flanges 32 alreadyfolded horizontally outwards span the gap between the lower edges of thewalls of the tray and thelower edges of the panels 26 and 28 of thestrip except for the area in the vicinity of the fold lines 30. In theseareas L-shaped cavities 50 are formed by the walls 12 and '14 of thetray, the horizontal flange portions 18 and 20 and the panels 26 and 28best seen in FIG. 8. The cavities 50 coincide with the triangularapertures 9.

The trays are stacked by superimposing one tray upon another; the bottom2 of each tray resting-on the shoulder provided by the upper edge of thestrip C of the tray below, the angled projections of the tray belowengaging the apertures 9 in the bottom 2 of the tray above.

One or more stacks of trays of either embodiment can conveniently behoused in a cardboard or like outer container, provided with an openingfor easy withdrawal of a stack or part of a stack. Referring to FIG. 12an outer container 52 has an end opening which is closable by means offlaps hinged around its periphery. The lower flap 54 is first turned up.Then the 'side flaps 56, 58 are folded in, the flap 56 first, and a tab60 on the flap 58 engaging in a slot 62 in the flap As has already beenobserved in respect of the first v any such flat condition from whichthe tray can be erected. It may for example be in a form where theadhered side walls are folded in flat on the bottom instead of lyingfiat adjacent the bottom as shown. In this case the second panel mayhave to be slightly less high than the first in order to enable thewalls to be erected without damage. A difference of about 2mm. has beenfound satisfactory in many cases.

The trays described are made of cardboard or like material but otherembodiments can be made in plastics material, in which case they couldbe integrally moulded into the required shape if desired. .The trays mayhave walls on only threesides if desired.

The trays described are particularly suitable for fragile articles, andone particular use is in the catering trade where itis desired topre-pack meals, for example for consumption on an aircraft passengerflight. In this case the food and the. implements required for consumingit, may be placed in the trays which are stacked one above the other inthe manner described, and the stack is then slid intothe. outercontainer 52 which is then closed. An appropriate number of filledcontainers are taken on board the aircraft and, when it is desired topartake of the meal, the hostess withdraws all or part of the stack fromthe container and delivers a filled tray to each passenger starting atthe top of the stack. When the meal is finished, the trays together withany unconsumed food are restacked and again placed in the outercontainer, which is disposed of together with the con- .tents at the endof the journey.

The tray and its method of use is a great advantage over the existingsystem where trays are housed in a relatively heavy aluminum containerfitted with runners and withdrawn singly. Only three or four trays canbe distributed at one time. Such trays and containers also need to bewashed for re-use. The present trays and containers are cheaper,lighter, can be carried in 56. Then the top flap 64 is folded down andits end tab 66 inserted through superimposed slots 68 in the side flaps.The tab 66 is held in the near vertical position by being trappedbetween the side flap 56 and the stack of containers. A C-shaped slot 70in the side flap '58 provides a tongue 72 by which the container can bepulled from a stack of similar containers.

When the trays are for containing food, the container is preferably madeof cardboard with an external coating of aluminum foil or otherimpermeable film so that externally produced odors are not absorbed bythe cardboard and transmitted to the food. The container illustrated isparticularly suitable where it may be exposed to rain, since the flap 64greatly reduces the chance of rain getting into the container.

greater numbers, and can be discarded after use.

Other uses for the tray made according to this invention are to be foundfor example on sports grounds, at gardenparties and like functions, andin schools and hospitals. The trays can also be used for the transportof fragile articles.

One useful feature which is shown in both of the embodiments describedis that of having at least a part of one wall lower than the otherthree. This is particularly important in trays for food where the foodis to be eaten with utensils straight from the tray. It is inconvenientfor the diner to have to operate over a high wall on the tray, yethaving a low wall all round would unduly restrict the size of articlewhich could be contained in the tray when stacked. A similar advantagecould be obtained with trays of the present invention if two oppositewalls have lower portions. Where projections are provided only on twocorners, the opposite wall, instead of being merely lower, could beabsent altogether.

What I claim' and desire to secure by Letters Patent l. A stackable traycomprising a bottom having an aperture in each of at least two cornerregions, walls extending upwardly and inwardly from the bottom andincluding in each of at least two corner regions a pair of cornerforming panels extending one along each of the adjacent sides of thetray and having a single integral projection lying in the plane of thepanel to which it is integral and extending upwardly above the height ofthe adjacent walls and laterally around the comer, the projections andapertures in the tray being arranged so that two similar trays can bestacked one on the other with the projections of the lower tray engagingin the apertures of the upper tray and the projections are reinforced bytheir engagement with the apertures.

2. A stackable tray made from foldable sheet material, comprising abottom, hinged to the bottom a pair of opposite side walls and a thirdside wall extending between them, said third wall having lateral flapshinged thereto, and each wall of said pair comprising a first panelhinged to the bottom and a second panel hinged to the first panel andfolded to trap the adjacent lateral flaps between the panels and therebymaintain the walls in the erect condition, said third wall and itslateral flaps being shaped to provide at each corner.

between them an integral projection extending upwardly above the heightof the adjacent walls and laterally around the comer, the bottom beingprovided with apertures arranged so that two similar trays can bestacked one on the other with the projections of the lower tray engagingin the apertures of the upper tray.

3. A tray according to claim 2 having a fourth side wall opposite saidthird wall, and lateral flaps hinged to the fourth wall and trappedbetween the first and second panels of said pair of opposite walls, thefourth wall comprising a first panel hinged to the bottom, and a secondpanel defined at least in part by a pair of cuts extending into thefirst panel from its upper edge and a hinge line extending parallel tosaid other edge between the lower ends of the cut, the second panelbeing folded about the hinge line to provide in the fourth wall arelatively lower portion.

4. A tray according to claim 2 wherein the part of each projection whichextends from a lateral flap passes upwardly through a cut-away portionof the adjacent wall of said pair.

5. A tray according to claim 2 wherein said third wall comprises a firstpanel hinged to the bottom, a second panel hinged to the outer end ofthe first panel and folded back on the first panel and secured in thatcondition, the lateral flaps being hinged to one of the panels, and eachprojection being provided in part by an L-shaped cut at the end of thehinge line between the two panels and extending from the hinge line intothe panel not carrying the lateral flaps.

6. A stackable tray comprising a bottom having an aperture in each of atleast two corner regions, walls extending upwardly from the bottom andincluding in each of at least two comer regions a pair of comer formingpanels extending one along each of the adjacent sides of the tray andhaving a single integral projection extending upwardly above the heightof the adjacent walls and laterally around the corner, the projectionsand apertures in the tray being arranged so that two similar trays canbe stacked one on the other with the projections of the lower trayengaging in the apertures of the upper tray, the wall of the trayincluding an outer wall forming part, an inner wall forming part fittinginside the outer part and comprising a strip of panels hinged one to thenext, and means for retaining the strip within the tray, the upper edgeof the strip being shaped in the region of the hinges to provide theprojections.

7. A tray according to claim 6 wherein the retaining means compriseshorizontal webs of material extending diagonally across the comersbetween adjacent outer wall panels engaging in corresponding horizontalslots provided in the strip in the region of its hinges and extendinginto the adjacent panels.

8. A tray according to claim 6 wherein the outer wall panels of the trayare provided with an inturned peripheral flange providing spacing meansbetween the outer wall panels and the strip.

9. A blank of foldable sheet material for erecting into a stackable traycomprising a bottom and side walls extending upwardly therefrom, theblank comprising a bottom fonning panel and hinged to the bottom formingpanel a pair of opposite side wall forming portions and a third sidewall forming portion extending between them said third side wall formingportion having hinged lateral flaps, each wall forming portion of saidpair comprising a first panel hinged to the bottom forming panel and asecond panel hinged to the free end of the first panel, the lateralflaps and said third side wall forming portion being shaped in theregion of their common hinges to provide in the erect condition of thetray an integral projection extending laterally around the corner ateach hinge and upwardly above the height of the adjacent walls, thesecond panels of the wall forming portions of the pair being foldable totrap the lateral flaps between the first and second panels and maintainthe tray in the erect condition, the bottom forming panel being providedwith apertures located so that when similar trays are stacked theprojections of one tray may engage in the apertures of the tray nextabove.

, 10. A blank according to claim 9 wherein said third wall formingportion comprises a first panel hinged to the bottom and a second panelhinged to the free end of the first panel, the second panel of each wallforming portion having hinged to its free end a flange, the flangesbeing adapted'so that in the erect condition of the tray they can lie onthe bottom and extend inwardly from their respective walls with the endedges of the flange of said third wall abutting the free edges of theflanges of said pair of walls.

11. A stackable tray made from foldable sheet material, comprising abottom, hinged to the bottom a pair of opposite side walls and a thirdside wall extending between them, said third wall having lateral flapshinged thereto, and each wall of said pair comprising a first panelhinged to the bottom and a second panel hinged to the first panel andfolded to trap the adjacent lateral flaps between the panels and therebymaintain the walls in the erect condition, said third wall and itslateral flaps being shaped to provide at each corner between them anintegral projection extending upwardly above the height of the adjacentwalls and laterally around the comer, the bottom being provided withapertures arranged so that two similar trays can be stacked one on theother with the projections of the lower tray engaging in the aperturesof the upper tray, said second panels of said pair of walls being foldedinwardly to trap the lateral flaps, and the second panel of each wallhaving hinged to it a flange which lies on the bottom and faces inwardlyfrom the wall, the length of the flange of said third wall being suchthat its ends it abuts the edges of the flanges of said pair of wallsand maintains the second panels of said pair in the folded in condition.

12. A stackable tray made from foldable sheet material, comprising abottom, hinged to thebottom a pair of opposite side walls and a thirdside wall extending between them, said third wall having lateral flapshinged thereto, and each wall of said pair comprising-a first panelhinged to the bottom and a second panel hinged to the first panel andfolded to trap the adjacent lateral flaps between the panels and therebymaintain the, walls in the erect condition, said third wall and itslateral flaps being shaped to provide at each comer between them anintegral projection extending up wardly above the height ofthe adjacentwalls and laterally around the corner, the bottom being provided withapertures arranged sothat two similar trays can be material, comprisinga bottom, hinged to the bottom a pair of opposite side walls and a thirdside wall extending between them, said third wall having lateral flapshinged thereto, and each wall of said pair comprising a first panelhinged to the bottom and a second panel hinged to the first panel andfolded to trap the adjacent lateral flaps between the panels and therebymaintain the walls in the erect condition, said third wall and itslateral flaps being shaped to provide at each corner stacked one on theother with the projections of the lower tray engaging in the aperturesof the upper tray a fourth side wall opposite said third wall, andlateral flaps hinged to the fourth wall and trapped between the firstand second panels of said pair of opposite walls, the fourth wallcomprising a first panel hinged to the bottom, and a second paneldefined at least in part by a pair of cuts extending into the firstpanel from its upper edge and a hinge line extending parallel to saidother edge between the lower ends of the cut, the second panel beingfolded about the hinge line to provide in between them an integralprojection extending upwardly above the height of the adjacent walls andlaterally around the comer, the bottom being provided with aperturesarranged so that two similar trays can be stacked one on the other withthe projectionsof the lower tray engaging in the apertures of the uppertray, the outer of the two panels of said third wall being provided withthe lateral flaps and the inner of the two being arranged to flexinwardly relative to the tray so that the adjacent ends of the secondpanels of said pair of walls are trapped between the lateral flaps andthe ends of the inwardly flexed panel.

1. A stackable tray comprising a bottom having an aperture in each of atleast two corner regions, walls extending upwardly and inwardly from thebottom and including in each of at least two corner regions a pair ofcorner forming panels extending one along each of the adjacent sides ofthe tray and having a single integral projection lying in the plane ofthe panel to which it is integral and extending upwardly above theheight of the adjacent walls and laterally around the corner, theprojections and apertures in the tray being arranged so that two similartrays can be stacked one on the other with the projections of the lowertray engaging in the apertures of the upper tray and the projections arereinforced by their engagement with the apertures.
 2. A stackable traymade from foldable sheet material, comprising a bottom, hinged to thebottom a pair of opposite side walls and a third side wall extendingbetween them, said third wall having lateral flaps hinged thereto, andeach wall of said pair comprising a first panel hinged to the bottom anda second panel hinged to the first panel and folded to trap the adjacentlateral flaps between the panels and thereby maintain the walls in theerect condition, said third wall and its lateral flaps being shaped toprovide at each corner between them an integral projection extendingupwardly above the height of the adjacent walls and laterally around thecorner, the bottom being provided with apertures arranged so that twosimilar trays can be stacked one on the other with the projections ofthe lower tray engaging in the apertures of the upper tray.
 3. A trayaccording to claim 2 having a fourth side wall opposite said third wall,and lateral flaps hinged to the fourth wall and trapped between thefirst and second panels of said pair of opposite walls, the fourth wallcomprising a first panel hinged to the bottom, and a second paneldefined at least in part by a pair of cuts extending into the firstpanel from its upper edge and a hinge line extending parallel to saidother edge between the lower ends of the cut, the second panel beingfolded about the hinge line to provide in the fourth wall a relativelylower portion.
 4. A tray according to claim 2 wherein the part of eachprojection which extends from a lateral flap passes upwardly through acut-away portion of the adjacent wall of said pair.
 5. A tray accordingto claim 2 wherein said third wall comprises a first panel hinged to thebottom, a second panel hinged to the outer end of the first panel andfolded back on the first panel and secured in that condition, thelateral flaps being hinged to one of the panels, and each projectionbeing provided in part by an L-shaped cut at the end of the hinge linebetween the two panels and extending from the hinge line into the panelnot carrying the lateral flaps.
 6. A stackable tray comprising a bottomhaving an aperture in each of at least two corner regions, wallsextending upwardly from the bottom and including in each of at least twocorner regIons a pair of corner forming panels extending one along eachof the adjacent sides of the tray and having a single integralprojection extending upwardly above the height of the adjacent walls andlaterally around the corner, the projections and apertures in the traybeing arranged so that two similar trays can be stacked one on the otherwith the projections of the lower tray engaging in the apertures of theupper tray, the wall of the tray including an outer wall forming part,an inner wall forming part fitting inside the outer part and comprisinga strip of panels hinged one to the next, and means for retaining thestrip within the tray, the upper edge of the strip being shaped in theregion of the hinges to provide the projections.
 7. A tray according toclaim 6 wherein the retaining means comprises horizontal webs ofmaterial extending diagonally across the corners between adjacent outerwall panels engaging in corresponding horizontal slots provided in thestrip in the region of its hinges and extending into the adjacentpanels.
 8. A tray according to claim 6 wherein the outer wall panels ofthe tray are provided with an inturned peripheral flange providingspacing means between the outer wall panels and the strip.
 9. A blank offoldable sheet material for erecting into a stackable tray comprising abottom and side walls extending upwardly therefrom, the blank comprisinga bottom forming panel and hinged to the bottom forming panel a pair ofopposite side wall forming portions and a third side wall formingportion extending between them said third side wall forming portionhaving hinged lateral flaps, each wall forming portion of said paircomprising a first panel hinged to the bottom forming panel and a secondpanel hinged to the free end of the first panel, the lateral flaps andsaid third side wall forming portion being shaped in the region of theircommon hinges to provide in the erect condition of the tray an integralprojection extending laterally around the corner at each hinge andupwardly above the height of the adjacent walls, the second panels ofthe wall forming portions of the pair being foldable to trap the lateralflaps between the first and second panels and maintain the tray in theerect condition, the bottom forming panel being provided with apertureslocated so that when similar trays are stacked the projections of onetray may engage in the apertures of the tray next above.
 10. A blankaccording to claim 9 wherein said third wall forming portion comprises afirst panel hinged to the bottom and a second panel hinged to the freeend of the first panel, the second panel of each wall forming portionhaving hinged to its free end a flange, the flanges being adapted sothat in the erect condition of the tray they can lie on the bottom andextend inwardly from their respective walls with the end edges of theflange of said third wall abutting the free edges of the flanges of saidpair of walls.
 11. A stackable tray made from foldable sheet material,comprising a bottom, hinged to the bottom a pair of opposite side wallsand a third side wall extending between them, said third wall havinglateral flaps hinged thereto, and each wall of said pair comprising afirst panel hinged to the bottom and a second panel hinged to the firstpanel and folded to trap the adjacent lateral flaps between the panelsand thereby maintain the walls in the erect condition, said third walland its lateral flaps being shaped to provide at each corner betweenthem an integral projection extending upwardly above the height of theadjacent walls and laterally around the corner, the bottom beingprovided with apertures arranged so that two similar trays can bestacked one on the other with the projections of the lower tray engagingin the apertures of the upper tray, said second panels of said pair ofwalls being folded inwardly to trap the lateral flaps, and the secondpanel of each wall having hinged to it a flange which lies on the bottomand faces inwardly from the wall, The length of the flange of said thirdwall being such that at its ends it abuts the edges of the flanges ofsaid pair of walls and maintains the second panels of said pair in thefolded in condition.
 12. A stackable tray made from foldable sheetmaterial, comprising a bottom, hinged to the bottom a pair of oppositeside walls and a third side wall extending between them, said third wallhaving lateral flaps hinged thereto, and each wall of said paircomprising a first panel hinged to the bottom and a second panel hingedto the first panel and folded to trap the adjacent lateral flaps betweenthe panels and thereby maintain the walls in the erect condition, saidthird wall and its lateral flaps being shaped to provide at each cornerbetween them an integral projection extending upwardly above the heightof the adjacent walls and laterally around the corner, the bottom beingprovided with apertures arranged so that two similar trays can bestacked one on the other with the projections of the lower tray engagingin the apertures of the upper tray a fourth side wall opposite saidthird wall, and lateral flaps hinged to the fourth wall and trappedbetween the first and second panels of said pair of opposite walls, thefourth wall comprising a first panel hinged to the bottom, and a secondpanel defined at least in part by a pair of cuts extending into thefirst panel from its upper edge and a hinge line extending parallel tosaid other edge between the lower ends of the cut, the second panelbeing folded about the hinge line to provide in the fourth wall arelatively lower portion, said second panels of said pair of walls beingfolded inwardly to trap the lateral flaps, and the second panel of eachwall having hinged to it a flange which lies on the bottom and facesinwardly from the wall, the length of the flanges of the third andfourth walls being such that at their ends they abut the edges of theflanges of said pair of walls and maintain the second panels of saidpair in the folded in condition.
 13. A stackable tray made from foldablesheet material, comprising a bottom, hinged to the bottom a pair ofopposite side walls and a third side wall extending between them, saidthird wall having lateral flaps hinged thereto, and each wall of saidpair comprising a first panel hinged to the bottom and a second panelhinged to the first panel and folded to trap the adjacent lateral flapsbetween the panels and thereby maintain the walls in the erectcondition, said third wall and its lateral flaps being shaped to provideat each corner between them an integral projection extending upwardlyabove the height of the adjacent walls and laterally around the corner,the bottom being provided with apertures arranged so that two similartrays can be stacked one on the other with the projections of the lowertray engaging in the apertures of the upper tray, the outer of the twopanels of said third wall being provided with the lateral flaps and theinner of the two being arranged to flex inwardly relative to the tray sothat the adjacent ends of the second panels of said pair of walls aretrapped between the lateral flaps and the ends of the inwardly flexedpanel.